Aspergillosis is an infection caused by a type of mold. The illnesses resulting from aspergillosis infection usually affect the respiratory system, but their signs and severity vary greatly. The mold that triggers the illnesses, aspergillus, is everywhere, indoors and outdoors. Most strains of this mold are harmless, but a few can cause serious illnesses when people with weakened immune systems, underlying lung disease or asthma inhale their spores.

In some people, the spores trigger an allergic reaction. Other people develop mild to serious lung infections. The most serious form of aspergillosis — invasive aspergillosis — occurs when the infection spreads to blood vessels and beyond.

The signs and symptoms of aspergillosis vary with the type of illness you develop:

Allergic reaction

Some people with asthma or cystic fibrosis have an allergic reaction to aspergillus mold. Signs and symptoms of this condition, known as allergic bronchopulmonary aspergillosis, include:

Fever

A cough that may bring up blood or plugs of mucus

Worsening asthma

Fungal mass

A growth of tangled fungus fibers (fungus ball) may develop in air spaces (cavities) in the lung as part of chronic pulmonary aspergillosis. This type of aspergillosis is called simple aspergilloma. Lung cavities may develop in people with pre-existing lung conditions, such as emphysema, tuberculosis or advanced sarcoidosis.

Aspergilloma is a benign condition that may not produce symptoms or may produce a mild cough only, but over time, the underlying condition can worsen and possibly cause:

A cough that often brings up blood (hemoptysis), sometimes large amounts

Wheezing

Shortness of breath

Unintentional weight loss

Fatigue

Infection

Invasive pulmonary aspergillosis — the most severe form — occurs when the infection spreads rapidly from the lungs to your brain, heart, kidneys or skin. This occurs only in people whose immune system is weakened, commonly from chemotherapy. Untreated, this form of aspergilla disease is usually fatal.

Signs and symptoms depend on which organs are affected, but in general, invasive aspergillosis can cause:

Fever and chills

Cough that brings up blood-streaked sputum (hemoptysis)

Severe bleeding from your lungs

Shortness of breath

Chest or joint pain

Headaches or eye symptoms

Nosebleed

Facial swelling on one side

Skin lesions

Other types of aspergillosis

Aspergillus can invade areas of the body other than your lungs, such as your sinuses. In your sinuses, it can cause a stuffy nose, drainage that's possibly bloody, inflammation, fever, facial pain and headache.

When to see a doctor

If you have asthma or cystic fibrosis, see your doctor whenever you notice a change in your symptoms. Although aspergillosis may not be the cause, it's important to have problems evaluated.

If you have a weakened immune system and develop an unexplained fever, shortness of breath or a cough that brings up blood, get immediate medical care. In the case of invasive aspergillosis, prompt treatment is crucial, and treatment is sometimes started before the infection is diagnosed.

Aspergillus mold is unavoidable. Outdoors, it's found in decaying leaves and compost and on plants, trees and grain crops. Inside, the spores — the reproductive parts of mold — thrive in air conditioning and heating ducts, insulation, and some food and spices.

Everyday exposure to aspergillus is rarely a problem for people with healthy immune systems. When mold spores are inhaled, immune system cells surround and destroy them. But people who have a weakened immune system from illness or immunosuppressant medications have fewer infection-fighting cells. This allows aspergillus to take hold, invading the lungs and, in the most serious cases, other parts of the body.

Aspergillosis is not contagious from person to person.

Your risk of developing aspergillosis depends on your overall health and the extent of your exposure to mold. In general, these factors make you more vulnerable to infection:

Weakened immune system. People taking immune-suppressing drugs after undergoing transplant surgery — especially bone marrow or stem cell transplants — or people who have certain cancers of the blood are at highest risk of invasive aspergillosis. People in the later stages of AIDS also may be at increased risk.

Low white blood cell level. Having chemotherapy, an organ transplant or leukemia lowers your white cell level, making you more susceptible to invasive aspergillosis. So does having chronic granulomatous disease — an inherited disorder that affects immune system cells.

Lung cavities. People who have healed air spaces (cavities) in their lungs are at higher risk of developing a mass of tangled fungus fibers (aspergilloma). Cavities are areas that have been damaged by radiation to the lung or by lung diseases such as tuberculosis or sarcoidosis — a noncancerous, inflammatory illness.

Asthma or cystic fibrosis. People with asthma and cystic fibrosis, especially those whose lung problems are long-standing or hard to control, are more likely to have an allergic response to aspergillus mold.

Long-term corticosteroid therapy. Long-term use of corticosteroids may increase the risk of opportunistic infections, depending on the underlying disease being treated and what other drugs are being used.

Depending on the type of infection, aspergillosis can cause a variety of serious complications:

Bleeding. Both aspergillomas and invasive aspergillosis can cause severe, and sometimes fatal, bleeding in your lungs.

Systemic infection. The most serious complication of invasive aspergillosis is the spread of the infection to other parts of your body, especially your brain, heart and kidneys. Invasive aspergillosis spreads rapidly and is often fatal in spite of early treatment.

People who develop aspergillosis usually have an underlying condition, such as asthma or cystic fibrosis, or have a weakened immune system due to illness or to immune-suppressing medications. If you have symptoms of aspergillosis and are already being treated for a medical condition, call the doctor who provides your care for that condition. In some cases, when you call to set up an appointment, your doctor may recommend urgent medical care.

If you have a weakened immune system and develop an unexplained fever, shortness of breath or a cough that brings up blood, seek immediate medical care.

If you have time to prepare before seeing your doctor, here's some information to help you get ready for your appointment.

What you can do

Be aware of any pre- or post-appointment restrictions. When you call for the appointment, ask if there's anything you need to do in advance.

Write down your key medical information. If you are going to see a new doctor, bring a summary of other conditions for which you're being treated, as well as recent medical appointments or hospitalizations.

Bring all of your medications with you, preferably in their original bottles. If the doctor you are seeing doesn't have access to your medical records or previous imaging tests, such as X-rays or CT scans, try to get copies to take with you.

Take along a family member or friend. Aspergillosis can be a medical emergency. Take someone who can understand and recall all the information your doctor provides and who can stay with you if you need immediate treatment.

Write down questions to ask your doctor.

Prepare a list of questions so that you can make the most of your time with your doctor. For aspergillosis, some basic questions to ask your doctor include:

What is likely causing my symptoms?

Other than the most likely cause, what are other possible causes for my symptoms?

What tests do I need?

Do I need to be hospitalized?

What treatment do you recommend?

What are the possible side effects from the medications you're recommending?

How will you monitor my response to treatment?

Am I at risk of long-term complications from this condition?

I have another health condition. How can I best manage these conditions together?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you some questions, including:

What are your symptoms?

Have you seen other doctors for this?

When did you begin experiencing symptoms?

How severe are your symptoms? Do they seem to be getting worse?

Have you had a fever?

Are you having difficulty breathing?

Are you coughing up blood?

What else concerns you?

Diagnosing an infection caused by aspergillus mold can be difficult and depends on the type of aspergillus infection. Aspergillus is common in the environment and is sometimes found in the saliva and sputum of healthy people. What's more, it's hard to distinguish aspergillus from certain other molds under the microscope, and symptoms of the infection are similar to those of conditions such as tuberculosis.

Your doctor is likely to use one or more of the following tests:

Imaging test. A chest X-ray or computerized tomography (CT) scan — a type of X-ray that produces more-detailed images than conventional X-rays do — can usually reveal a fungal mass (aspergilloma), as well as characteristic signs of invasive and allergic bronchopulmonary aspergillosis.

Respiratory secretion (sputum) test. In this test, a sample of your sputum is stained with a dye and checked for the presence of aspergillus filaments. The specimen is then placed in a culture that encourages the mold to grow to help confirm the diagnosis.

Tissue and blood tests. Skin, sputum and blood tests may be helpful in confirming allergic bronchopulmonary aspergillosis. For the skin test, a small amount of aspergillus antigen is injected into the skin of your forearm. If your blood has antibodies to the mold, you'll develop a hard, red bump at the injection site. Blood tests look for high levels of certain antibodies, indicating an allergic response.

Biopsy. In some cases, examining a sample of tissue from your lungs or sinuses under a microscope may be necessary to confirm a diagnosis of invasive aspergillosis.

Observation. Simple, single aspergillomas often don't need treatment, and medications aren't usually effective in treating these fungal masses. Instead, aspergillomas that don't cause symptoms may simply be closely monitored by chest X-ray. If the condition progresses, then antifungal medications may be recommended.

Oral corticosteroids. The goal in treating allergic bronchopulmonary aspergillosis is to prevent existing asthma or cystic fibrosis from worsening. The best way to do this is with oral corticosteroids. Antifungal medications by themselves aren't helpful for allergic bronchopulmonary aspergillosis, but they may be combined with corticosteroids to reduce the dose of steroids and improve lung function.

Antifungal medications. These drugs are the standard treatment for invasive pulmonary aspergillosis. Historically, the drug of choice has been amphotericin B, but the newer medication voriconazole (Vfend) is now preferred because it appears to be more effective and may have fewer side effects.

All antifungals can cause serious problems, however, including kidney and liver damage, and they frequently interact with other medications given to people who have weakened immune systems.

Surgery. Because antifungal medications don't penetrate aspergillomas very well, surgery to remove the fungal mass is the first-choice treatment when bleeding from the mass in the lungs occurs. But the surgery is risky, and your doctor may instead suggest embolization.

In this procedure, a radiologist threads a small catheter into the artery that supplies blood to the cavity containing the fungus ball and injects a material that clogs the artery. Though this procedure can stop massive bleeding, it doesn't prevent it from recurring, so it's generally considered a temporary treatment.

It's nearly impossible to avoid exposure to aspergillus, but if you have had a transplant or are undergoing chemotherapy, try to stay away from the most obvious sources of mold, such as construction sites, compost piles and stored grain. If you have a weakened immune system, your doctor may advise you to wear a face mask to avoid being exposed to airborne infectious agents.

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